Conventionally, in a vehicle, such as a hybrid vehicle having a motor drive device, a cooperative control (regeneration cooperative control) by the regeneration braking and the hydraulic pressure braking is performed in the braking operation. In view point of fuel efficiency, the regeneration braking is used in priority to the hydraulic pressure braking. The brake ECU calculates the braking force shortage by subtracting the regeneration braking force from the required braking force and then controls the hydraulic pressure braking force generating device to generate the calculated braking force shortage.
In a regeneration cooperative control, since there is a limit to generation of the regeneration braking force, a replacement, in which a transition is made from a braking state where the braking is performed mainly by the regeneration braking force to a braking state where the braking is performed by increasing the hydraulic pressure braking force, is executed to supplement the limited regeneration braking force. By this replacement execution of the braking state, a problem has been pointed out that a response delay may occur depending on the control performance characteristics of the hydraulic pressure brake such as setting of deadband. Such response delay may influence on the brake operation feeling for an operator of the vehicle. In more detail, sometimes such response delay may have the operator of the vehicle temporarily feel that the brakes are weak.
Accordingly, the brake control devices described in the patent literatures JP2009-154600A and JP2010-167972A have solved the above problem by raising the target pressure at the timing of execution of the replacement thereby to smoothly increase the actual pressure.